Grinding machine



March 1 1927.

M. M. KAUFMANN iET AL v GRINDING MACHINE 5 Sfieets-Sheet Filed May 7,1925 March -1, 1927.

M. M. KAUFMANN ET AL GRINDING MACHINE Filed May 7, 1925 I 3 Sheets-Sheet2 m .\N m B W /m m m w m i -i v Iii Fl liiiyl a s? m" illI 25 n L. \VWfi/ 1 w 7; 1 a T\\ L :2; lm giih EVE MN MN] Nun-fin? L ink 1 1.1:: Qswa WM MW &KNXE w M Q N um Q m fi $1 bfi 7 m g 161 ,-76 March M. M.KAUFMANN ET AL 9 GRINDING MACHINE Filed May {7, 1925 5 Sheets-Sheet 3Patented Mar. 1, 1927.

UNITED STATES PATENT orFicE.

MICHAEL M. KAUFMANN, JOHN P. LYNN, AND FRANK C. DELI, OF CHICAGO,ILLINOIS, ASSIGNORS TO AUTOPOINT COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS.

GRINDING MACHINE.

Application filed May 7, 1925. Serial No. 23,596.

Our invention relates to grinding machmes and particularly to a machlneadapted to simultaneously grind two of the polygonal sides of a pencilbody or barrel.

The pencils of a certainwell-known type have bodies composed of aphenolic condensation product such as bakelite. This prodnot is veryhard, and where the bodies are to be transparent or translucent, it isnecessary to grind the material to the desired shape, inasmuch asitcannot be molded.

The machine of our invention is intended to accomplish the grindingoperation very quickly, accurately and simply. Two sides aresimultaneously ground, the grinding wheels rotating in oppositedirections, thus avoiding the necessity for grasping the blank firmly toprevent its rotation. A. further advantage in the machine is that itpermits the bodies to be ground completely from end to end, the blankbeing held merely by centralizing spindles. Suitable means are providedfor insuring accuracy and facility in operation and these will behereinafter described.

The invention will be more readily understood by reference to theaccompanying drawings, in which:

Fig. 1 is an end view of the machine constructed in accordance with ourinvention,

Fig. 2 is a plan view thereof,

Fig. 3 is a longitudinal sectional view taken on the line 33 of Fig. 2.

Fig. 4 is a sectional view taken on the line 4-4- of Fig. 2.

Fig. 5 is an enlarged detail elevation of the indexing means forcontrolling the position of the blank;

Figs. 6 and 7 are side and end views respectively of the finished pencilbody; and,

Fig. 8 is a sectional view on the line 8-8 of Fig. 2. f

The machine comprises a base or bed 10, on which the operating mechanismis mount r ed. Supported on the base are plates 11, 12,

each carrying a slideway 13.,for co-operation with a slide 14. Mountedon each slide, in suitable bearings, is a shaft 15, and a belt pulley,16. On the overhung end of the shaft, 15, is mounted the grinding wheel17.

As best shown in Fig. 2, the slides 14 have yoke rods 18 projectingrearwardly therefrom, the ends of the rods being joined by a cross piece19. A. bolt 20, and spring 21, tend to move the slide rearwardly. It

will be noted that the parts described are duplicated on opposite sidesof the machine.

Mounted beneath the bed plate is a horizontal shaft 22, and a rightangularly disposed shaft 23, having an operating handle 24, connectedthereto, as shown in Fig. 1. An indicating sector 25, having graduationsthereon, is mounted adjacent to the handle, 24, in order to provide avisual indication of the extent of movement of the handle. Bevelledgears 26, connect thetwo shafts 22, 23, while at the ends of the shaft22 are provided bevelled gears 27 that engage with bevelled gears 28,fixed to vertical shafts 29,

each carrying a cam, 30, at its upper end,

the cam engaging, through a wear plate 31, with a block 32. This blockis connected to the slides 14,by means of a threaded bolt 33, one end ofwhich is held by a pin 34, in the slide 14, the threaded portion of thebolt extending through an apertured extension 35, on the block 32, andbeing held by means of graduated nuts 36, 37, on opposite sides of theextension. This provides for accurate adjustment of the slide 14 and thegrinding wheels, the graduations on the nuts assuring accuratepositioning of the two slides when such adjustment is necessary in orderto change the diameter of the pencil bodies or compensate for wear onthe grinding wheels. Stop pins 38, provided on the stationary andmovable parts obviate wear at other points of contact.

The mechanism just described provides for the necessary advancing andretracting of the grinding wheels following the insertion and removal ofa blank. The blank is held between the spindles 39, 40, carriedrespectively by a tail stock 41 and a head stock '42. The spindle 40,the end of which is squared, is carried by a spring pressed plunger 43,mounted in the head stock and adapted for reciprocation by means of thehandle 44. The plunger is slidable rela' tive to and rotatable with anindexing wheel 45. by means of a spline 45*, Fig. 4.

The wheel, 45, best shown in Fig. 5, has

fil

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notches, as shown. The position of the wheel is controlled by means ofthe arm, 47, pivoted at 4:8, and carrying a tooth or pawl, 49, adaptedto enter one of the grooves, 46. The arm is held downward by means ofthe spring 50. The wheel is rotated by means of the arm 51, carrying thepawl 52, the end of which enters one of the notches, 4'6, and a portion53 of which arm is adapted to corn tact and raise the arn'i 47 to liftthe tooth 49,

"-out of engagement.

Thus, at the point where the tooth 49 is out of engagement, the pawlwill drop into the next notch, and a reversal of movement of the arm 51,will effect rotation of the wheel in a counterclockwise direction.Adjustable stops, 5d, 55, control the extent of oscillation of the arms47 and 51.

The means for effecting longitudinal movement of the blank relative tothe grinding wheels is best shown in Fig; 8. The head and tail stocksare supported on a triangular slide 56, supported at its ends on thevertical posts 57, 58, secured to a base 56. The stocks are joined at apoint under neath the triangular slide 56, by means of the rack 59. Awheel 60, is fixed to a shaft 61, and is. actuated by means of the arm,62, best shown in, Fig. 1. By this means, the head and tail stocks arecaused to reciprocate and to move the blank A, indicated in dotted linesin Fig. 4, across the grinding faces of the wheels.

It will be noted by the arrows in Fig. 3.

l that the grinding wheels rotate in opposite directions and thus thereis no tendency of the blank to rotate. /Ve thereby avoid the necessityfor rigidly holding the blank except so far as the squared end of thespindle, 40, effects such holding.

A pipe, 63, for supplying a grinding liquid, is shown in Fig. 1. Guardsor aprons, 6 1:, 65, serve to deflect the liquid and the waste material[10111 the grinding operation.

The operation is as follows: A blank, indicated by dotted lines in Fig.l, and desig-v nated A, has been provided with centering recesses in itsends, the recesses being shown in the ground bodies illustratedin'Figures 6 and 7. The blank is inserted by bringing one of its endsinto contact with the fixed spindle or pointed pin, 39; its other endbeing engaged with the squared end oi the spindle 40, by retracting thespindle under the influence of the lever or handle a l. Assuming thegrinding wheels are rotating, the spacing thereof is adjusted by movingthe arm 24, and under ordinary circumstances, the handle will be movedonly partly through the permissible arc of movement as indicated by thesector. This provides for the roughing cu With the grinding wheels sopositioned, the operator actuates the arm 62 and causes travel of thestocks and blank between the grinding wheels, the tail stock tl, as bestshown in Fig; 8 being narrower than the width of a finished pencil body.Due to the large capacity of the grinding wheels, the cutting action isvery rapid, the blank being rapidly passed forward and back to itsoriginal position.

As soon as the blank is out of the plane of rotation of the grindingwheels, the arm 51 is raised to its limit, thereby disengaging theholding pawl 49. and permitting the pawl 52. to engage with anothernotch, whereupon the return movement of the arm 51 rotates the wheel 45and plunger 45 thus rotating the blank through 72 degrees.

Assuming a ten-sided pencil body is being ground four additionalroughing cuts are made as described, all without changing the adjustmentof the arm 24. Vhenthe ten sides have thus been roughly ground. the arm2-lis thrown to. its extreme righthand position, thus moving thegrinding wheels to their closest point as determined by the adjustmentof the nuts 36, 37., The finishing cuts arethereupon made and thepencil-body is complete.

Preferably grinding wheels of relatively large size are employed withthe result tha the ground surtaces are so, nearly plane as to beunobjection able, in other words, the slight curvature is imperceptibleto. the eye. The

bodies are then, except for a small amount of polishing,- in a finishedcondition.

The operation of. the machine is very simple the only opportunity forvariation being inthe extent of the roughing cut. As to. all otheroperations. the limits are fixed and no opportunity for error exists.

Obviously the exact form and arrangement of parts is not essential andwe do not wish to be limited except as indicated in the appended claims.

Vi e claim:

1. A machine for grinding the sides oi polygonal objects, comprising, ineombinm tion. a bed. a pair of slides thereon, grinding wheels mountedon said slides, means io: sinu'lltaneously moving said slides andgrinding wheels toward and from each other. spindles for holding thework. means 'for effecting bodily reciprocation of said spindles andwork laterally relative to the reciprocation oi? the slides, and means"for rotating the spindles. and work by a step by step movement.

2. A machine for grinding the sides of polygonal objects, comprising, incombination, a bed, a pair of slides thereon. grinding wheelsmounted onsaid slides, means for simultaneouslymoving said slides and grindingwheels toward and from each, other, head and tail stocks, means forholding work between said stocks, means for efiecting reciprocation ofsaid stocks and work across the grinding faces of said wheels, and meansfor rotating the work by a step by step movement to present differentfaces to the wheels.

3. A machine for simultaneously grinding two sides of a polygonal blankcomprising, in combination, a bed, a pair of grinding wheels in opposedrelation, means on said bed for effecting bodily movement of thegrinding wheels toward and away from each other, a pair of stocks, meansfor holding a blank in centered relation between the stocks, means foreffection reciprocation of the stocks whereby to move the blanklongitudis nally across the faces of the grinding wheels, means forrotating the grinding wheels in opposite directions and means foreffecting a step by step movement of the work.

41-. A machine for simultaneously grinding two sides of a polygonalblank, comprising in combination, a bed, a pair of grinding wheels inopposed relation, means on said bed for effecting bodily movement of thegrinding wheels toward and away from each other, a pair of stocks, meansfor holding a blank in centered relation between the stocks, means foreffecting reciprocation of the stock whereby to move the blanklongitudinally across the faces of the grinding wheels, means forrotating the grinding wheels in opposite directions, and means formanually turning the blank to present different faces to the grindingwheels.

5. A machine for simultaneously grinding two sides of a polygonal blankcomprising, in combination, a bed, a pair of grinding wheels in opposedrelation, means on said bed for effecting bodily movement of thegrinding wheels toward and away from each other, a pair of stocks, meansfor holding a blank in centered relation between the stocks, means foreffecting reciprocation of the stocks whereby to move the blanklongitudinally across the faces of the grinding wheels, means forrotating the grinding wheels in opposite directions, and means formanually effecting step by step rotation of the blank to presentdifferent faces to the grinding wheels,

6. A machine for simultaneously grinding two sides of a polygonal blankcomprising, in combination, a bed, a pair of grinding wheels in opposedrelation, means on said bed for effecting bodily movement of thegrinding wheels toward and away from each other, a pair of stocks, meansfor holding a blank in centered relation between the stocks, means foreffecting reciprocation of the stocks whereby to move the blank longitudinally across the faces of the grinding wheels, spindles carried bysaid stocks, one of said spindles being longitudinally slidable, andmeans for effecting step by step rotation of one of said spindles inorder to present different faces of the blank to the grinding wheels.

y 7. In a machine of the class described, the combination of a bed, apair of grinding wheels mounted thereon with capacity for bodilymovement toward and away from each other, a manually operable arm foreffecting movement of the said wheels within prede-tern'iined limits, apair of spindles adapted to receive a blank therebetween, manuallyoperable means for effecting reciprocation of the spindles and blankacross the grinding faces of the opposed grinding wheels, and manuallyoperable means for rotating said blank in predetermined stepby-steprelation.

8. A grinding machine comprising, in combination, a pair of opposedgrinding wheels, manually operable means for fixing the relativeseparation of the wheels within predetermined limits, means for holdinga blank, manually operable means for longitudinally moving said blankacross the faces of said grinding wheels whereby the sides of the blankare ground throughout the length of the blank, and manuallyoperablemeans for effecting step-by-step angular movement of the blank topresent different faces to the grinding wheels.

9. A grinding machine comp-rising, in combination, a pair of opposedgrinding wheels, manually operable means for fixing the spacing of thewheels within predetermined limits, means for holding a blank, manuallyoperable means forv longitudinally moving said blank across the faces ofsaid grinding wheels whereby the sides of the blank are groundthroughout the length of the blank. manually operable means foreffecting step-by-step angular movement of the blank to presentdifferent faces to the grinding wheels, said last named means includinga pawl and ratchet mechanism.

In testimony whereof we have affixed our signatures.

MICHAEL M. KAUFMANN. JOHN P. LYNN. FRANK O. DELI.

